Work piece having self-supporting gusset and method related thereto

ABSTRACT

A powder-derived, non-finished work piece includes a first body section that has a wall that spans in a vertical direction. The wall has a relatively thin thickness with respect to a length and a width of the wall. A second body section is arranged next to, but spaced apart from, the first body section. A gusset connects the first body section and the second body section. The gusset extends obliquely from the wall of the first body section with respect to the vertical direction such that the gusset is self-supporting. The first body section has a geometry that corresponds to an end-use component exclusive of the gusset.

BACKGROUND

Powder bed additive manufacturing, such as selective laser melting, isused to produce components in a layered manner. For instance, aturbomachine compressor vane structure is one component that can be madeby powder bed additive manufacturing. The compressor vane structure mayinclude a rail that supports numerous airfoil vanes. The compressor vanestructure is produced in a horizontal orientation, where the airfoilvanes and rail are built layer by layer from a trailing edge side of thevanes up toward a leading edge side of the vanes. A support is builtduring the fabrication process, and the vanes and rail are fabricated onthis underlying support. The support is fused to the trailing edge ofthe vanes but is not part of the compressor vane structure. The supportis therefore later removed.

SUMMARY

A powder-derived, non-finished work piece according to an exemplaryaspect of the present disclosure includes a first body section having awall spanning in a vertical direction. The wall has a relatively thinthickness with respect a length and a width of the wall. A second bodysection is located next to, but spaced apart from, the first bodysection. A gusset connects the first body section and the second bodysection. The gusset extends obliquely from the wall of the first bodysection with respect to the vertical direction such that the gusset isself-supporting, and the first body section has a geometry correspondingto an end-use component exclusive of the gusset.

In a further non-limiting embodiment of any of the foregoing examples,the first body section is an airfoil.

In a further non-limiting embodiment of any of the foregoing examples,the first body section and the second body section are airfoils.

In a further non-limiting embodiment of any of the foregoing examples,the gusset extends at an angle of 45°±5° with respect to the verticaldirection.

In a further non-limiting embodiment of any of the foregoing examples,the gusset extends at an angle of no greater than 70° with respect tothe vertical direction.

In a further non-limiting embodiment of any of the foregoing examples,the gusset includes a first section and a second section orientedperpendicularly to the first section.

In a further non-limiting embodiment of any of the foregoing examples,the first section is directly connected to the first body section andthe second section is directly connected to the second body section.

In a further non-limiting embodiment of any of the foregoing examples,the gusset includes a first section and a second section that areconnected between each other at an angle of no greater than 140°.

In a further non-limiting embodiment of any of the foregoing examples,the thickness of the wall is 0.15 centimeters or less.

In a further non-limiting embodiment of any of the foregoing examples,the wall extends from a base end to a tip end, and the gusset extendsfrom the tip end.

In a further non-limiting embodiment of any of the foregoing examples,the first body section and the second body section have dissimilargeometries.

A method of making a powder-derived, non-finished work piece accordingto an exemplary aspect of the present disclosure includes depositingmultiple layers of powdered material onto one another, and joining thelayers to one another with reference to computer design data whichrelates to a particular cross-section of a work piece that is to beproduced. The joining of the layers forms a first body section whichincludes a wall spanning in a vertical direction and has a relativelythin thickness with respect a length and a width of the wall, a secondbody section next to, but spaced apart from, the first body section, anda gusset that connects the first body section and the second bodysection. The gusset extends obliquely from the wall of the first bodysection with respect to the vertical direction such that the gusset isself-supporting, and the first body section has a geometry whichcorresponds to an end-use component exclusive of the gusset.

In a further non-limiting embodiment of any of the foregoing examples,the first body section and the second body section are airfoils.

In a further non-limiting embodiment of any of the foregoing examples,the gusset includes a first section and a second section orientedperpendicularly to the first section.

In a further non-limiting embodiment of any of the foregoing examples,the gusset includes a first section and a second section that areconnected between each other at an angle of no greater than 140°maximum.

In a further non-limiting embodiment of any of the foregoing examples,the wall extends from a base end to a tip end, and the gusset extendsfrom the tip end.

A method of controlling distortion in a powder-derived, non-finishedwork piece according to an exemplary aspect of the present disclosureincludes providing a work piece with a first body section that includesa wall spanning in a vertical direction and having a relatively thinthickness with respect a length and a width of the wall, and a secondbody section next to, but spaced apart from, the first body section. Thefirst body section is then reinforced to limit distortion thereof byproviding a gusset connecting the first body section and the second bodysection together. The gusset extends obliquely from the wall of thefirst body section with respect to the vertical direction such that thegusset is self-supporting. The first body section has a geometrycorresponding to an end-use component exclusive of the gusset.

A further non-limiting embodiment of any of the foregoing examplesincludes limiting distortion of the first body section using the gussetduring a post-powder processing process.

In a further non-limiting embodiment of any of the foregoing examples,the post-powder processing process is selected from the group consistingof thermal stress relieving, hot isostatic processing, solution heattreating, aging heat treating, grit blasting and combinations thereof.

A further non-limiting embodiment of any of the foregoing examplesincludes removing the gusset after the post-powder processing process.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features and advantages of the present disclosure willbecome apparent to those skilled in the art from the following detaileddescription. The drawings that accompany the detailed description can bebriefly described as follows.

FIG. 1 illustrates an example powder-derived, non-finished work piecehaving a self-supporting gusset.

FIG. 2 a powder-derived, non-finished work piece that includes vaneairfoil sections.

FIG. 3 shows a modified work piece where the second body section has adissimilar geometry from the first body section.

FIG. 4 shows another example work piece where the first body section andthe second body section are airfoil vanes that are supported on a rail.

FIG. 5 is a perspective view of the work piece of FIG. 4.

FIG. 6 is a finished stator vane structure derived from the work pieceshown in FIGS. 4 and 5.

FIG. 7 shows an example method of making a powder-derived, non-finishedwork piece.

FIG. 8 shows a method of controlling distortion in a powder-derived,non-finished work piece.

DETAILED DESCRIPTION

Powder bed additive manufacturing, such as selective laser melting, canbe used to produce components, such as turbomachine components. Due tothermal gradients and other factors in the powder bed, the orientationin which the component is produced in the bed influences the propertiesand quality of the component. For example, HPC (high pressurecompressor) Stators having a rail that supports numerous airfoil vanescan be produced in a horizontal orientation, layer by layer, from atrailing edge upwards toward a leading edge of the airfoil vanes. In thehorizontal orientation, a support is required underneath the trailingedge to support the vanes as they are built layer by layer. The supportstructure must then be removed by machining, which can affect thequality of the airfoil vanes. Moreover, the airfoil vanes haverelatively thin walls that are subject to distortion during cooling inthe powder fabrication process and/or from post-powder processingprocesses that are used to finish the compressor vane structure. Due tothe thin walls and distortion, the compressor vane structure cannot beaccurately fabricated in a vertical orientation. Similarly, otherthin-walled structures are also limited to being fabricated in certainorientations.

In this regard, as will be described in further detail below, compressorvane structures and other relatively thin-walled structures can beproduced in a vertical orientation by using a self-supporting gussetdisclosed herein. The self-supporting gusset is also produced in thefabrication process and reinforces the wall of the component to controldistortion during and after the powder fabrication process.

FIG. 1 schematically illustrates selected portions of an examplepowder-derived, non-finished work piece 20. As can be appreciated,although the work piece 20 can be a turbomachine vane structure, thisdisclosure is not limited to such structures and the examples herein canalso be applied to other structures.

In this example, the work piece 20 includes a first body section 22 thathas a wall 24 that spans in a vertical direction, as represented by axisA1. The wall 24 has a relatively thin thickness (t) with respect to alength of the wall along the vertical direction and a width of the wall24 taken perpendicularly to the length and the thickness (t). In oneexample, the thickness (t) of the wall 24 is 0.15 centimeters or lessand is thus subject to distortion from thermal cooling during powderprocessing and/or distortion during post-powder processing processes,such as thermal stress relieving, hot isostatic processing, solutionheat treating, aging heat treating and grit blasting. Although thisdisclosure is not so limited, thicknesses above 0.15 centimeters tend tobe less prone to distortion.

A second body section 26 is arranged next to, but spaced apart from, thefirst body section 22. A gusset 28 connects the first body section 22and the second body section 26 together.

In this example, the gusset 28 includes a first section 28 a thatextends along a central axis A2 and a second section 28 b that extendsalong a central axis A3. The gusset 28 extends obliquely from the wall24 of the first body section 22 with respect to the vertical direction(axis A1) such that the gusset 28 is self-supporting. In this example,the oblique direction is represented by the axis A2, the axis A3 orboth. For instance, the axis A2 of the first section 28 a of the gusset28 has an angle α1 with respect to the vertical direction (axis A1) thatis 45°±5°. Similarly, the axis A3 has an angle α2 with respect to thevertical direction (axis A1) that is also 45°±5°. In other examples, theangles α1 and α2 each have a maximum angle of 70° with respect to thevertical direction (axis A1), and the angles α1 and α2 have a maximumangle of 140° with respect to each other. The angles can be changed toreduce or minimize distortion of the individual vanes and at the sametime to allow for component manufacturing without a support structure.

The first section 28 a of the gusset 28 is directly connected to thefirst body section 22 and the second section 28 b of the gusset 28 isdirectly connected to the second body section 26. Further, in thisexample, the first body section 22 extends between a base 22 a at basesupport 30 (e.g., a rail) and a tip end 22 b. The gusset 28 extends fromthe tip end 22 b of the first body section 22. As can be appreciated,the gusset can alternatively extend from other locations along the firstbody section 22, although placement of the gusset 28 at the tip end 22 bfacilitates the later removal of the gusset 28.

In fabricating the work piece 20 using powder bed additivemanufacturing, such as selective laser melting, the work piece 20 isfabricated in a vertical fashion from a base 30 vertically upward towardthe gusset 28. In powder bed additive manufacturing, structures that areoriented within about 45° of vertical are self-supporting whilestructures that are more horizontally oriented require powder-fabricatedsupports underneath as they are built up layer by layer. In this regard,the gusset 28, with axes A2 and A3 that form respective angles α1 and α2that are 45°±5° to the vertical direction (axis A1), is self-supportingduring the powder fabrication process.

Upon completion of the powder bed additive manufacturing process to formthe work piece 20, the work piece 20 can be cooled and then furtherprocessed. During the cooling, at least the first body section 22 issubject to thermal distortion forces. The gusset 28 reinforces the firstbody section 22 and, in this example, also the second body section 26,to control or limit thermal distortion.

Upon full cooling, the work piece 20 can then be subjected topost-powder processing processes, as listed above. Rather than removingthe gusset 28 directly after the powder fabrication, the gusset 28 iskept during the post-powder processing processes to reinforce the firstbody section 22 and the second body section 26, to control or limitdistortion from these processes. Upon completion of any or all processesthat can cause distortion, the gusset 28 is then removed, as shown inFIG. 2.

FIG. 2 shows a finished component 20′. As can be appreciated bycomparison of FIGS. 1 and 2, the geometry of at least the first bodysection 22 corresponds to the finished first body section 22′ of thefinished component 20′, exclusive of the gusset 28. In this example, thegeometry of the second body section 26 and the base support 30′ likewisecorrespond to the respective finished second body section 26′ andfinished base support 30′. Thus, the geometries of the first bodysection 22 and the second body section 26 correspond to the finishedend-use component without the gusset 28. The gusset 28 serves as aprocessing aid but is then later removed and is thus not a part of thegeometry of the finished component 20′.

As can also be appreciated from a comparison of FIGS. 1 and 2, the firstbody section 22 and the second body section 26 in this example haveidentical geometries. Alternatively, FIG. 3 shows a modified work piece120 where the second body section 126 has a dissimilar geometry from thefirst body section 22. In this disclosure, like reference numeralsdesignate like elements where appropriate in reference numerals with theaddition of one-hundred or multiples thereof designate modified elementsthat are understood to incorporate the same features and benefits of thecorresponding elements. In this example, the second body section 126 isgenerally larger, at least in thickness, than the first body section 22.Thus, the gusset 28 need not be between similar thin-walled sections andmay instead be used, as shown in FIG. 3, between a thin-walled section(the first body section 22) and a larger section, the second bodysection 126 in this example.

FIG. 4 shows a side view of another example work piece 220. FIG. 5 showsa perspective view of the work piece 220. In this example, the firstbody section 222 and the second body section 226 are airfoil vanes thatare supported on a rail 230. The gussets 28 extend between adjacentairfoil vanes. As shown in FIG. 6, the gussets 28 are later removed,leaving the rail 230 and the airfoil vanes as the finished component220′.

The gusset 28 permits airfoil vanes and similar thin-walled structuresto be fabricated in the vertical direction rather than a horizontaldirection from the trailing edge to the leading edge. Such structurescould not previously be fabricated in such an orientation becausedistortion during cooling or from subsequent processes would render thecomponents unsuitable. However, by using the gussets 28 forreinforcement during and after the powder fabrication, such componentscan now be fabricated in the vertical orientation. Further, building acomponent, such as the compressor vane structure, in the verticalorientation eliminates the need for machining the trailing edge, as isnecessary with the horizontal orientation, and thus reduces fabricationcycle time and expense.

FIG. 7 illustrates an example method 50 of making a powder-derived,non-finished work piece, such as the work pieces 20/120/220. In thisexample, the method 50 includes steps 52 and 54. Step 52 includesdepositing multiple layers of powdered material onto one another andstep 54 includes joining the layers to one another with reference tocomputer design data, such as computer aided drafting data, that relatesto a particular cross-section of the work piece that is being produced.The joining of the layers forms the geometry of the work pieces20/120/220, as described above.

FIG. 8 illustrates a method 60 of controlling distortion in apowder-derived, non-finished work piece, such as any of the work pieces20/120/220 described herein. The method 60 includes steps 62 and 64.Step 62 includes providing a work piece with a first body section thathas a wall that spans in a vertical direction and a relatively thinthickness with respect to a length and a width of the wall, and a secondbody section that is next to, but spaced apart from, the first bodysection. Step 64 includes reinforcing the first body section to limitdistortion thereof by providing a gusset, such as gusset 28, connectingthe first body section and the second body section together.

Although a combination of features is shown in the illustrated examples,not all of them need to be combined to realize the benefits of variousembodiments of this disclosure. In other words, a system designedaccording to an embodiment of this disclosure will not necessarilyinclude all of the features shown in any one of the Figures or all ofthe portions schematically shown in the Figures. Moreover, selectedfeatures of one example embodiment may be combined with selectedfeatures of other example embodiments.

The preceding description is exemplary rather than limiting in nature.Variations and modifications to the disclosed examples may becomeapparent to those skilled in the art that do not necessarily depart fromthe essence of this disclosure. The scope of legal protection given tothis disclosure can only be determined by studying the following claims.

What is claimed is:
 1. A method of making a powder-derived, vane structures, the method comprising: depositing multiple layers of powdered material onto one another; joining the layers to one another with reference to computer design data relating to a particular cross-section of a work piece that is to be produced, wherein the joining of the layers forms: a first body section including a wall spanning in a vertical direction and having a relatively thin thickness with respect a length and a width of the wall, a second body section next to, but spaced apart from, the first body section, and a gusset connecting the first body section and the second body section, the gusset extending obliquely from the wall of the first body section with respect to the vertical direction such that the gusset is self-supporting, and the first body section having, exclusive of the gusset, an airfoil; subjecting the airfoil to a post-power processing process; and after the post-power processing removing the gusset to produce a finished vane structure.
 2. The method as recited in claim 1, wherein the first body section and the second body section are airfoils.
 3. The method as recited in claim 1, wherein the gusset includes a first section and a second section oriented perpendicularly to the first section.
 4. The method as recited in claim 1, wherein the gusset includes a first section and a second section that are connected between each other at an angle of no greater than 140° maximum.
 5. The method as recited in claim 1, wherein the wall extends from a base end to a tip end, and the gusset extends from the tip end.
 6. A method of controlling distortion in a powder-derived vane structure, the method comprising: providing a work piece with a first body section including a wall spanning in a vertical direction and having a relatively thin thickness with respect a length and a width of the wall, a second body section next to, but spaced apart from, the first body section; reinforcing the first body section to limit distortion thereof by providing a gusset connecting the first body section and the second body section together, the gusset extending obliquely from the wall of the first body section with respect to the vertical direction such that the gusset is self-supporting, the first body section having, exclusive of the gusset, an airfoil; subjecting the airfoil to a post-power processing process; and after the post-powder processing, removing the gusset to produce a finished vane structure.
 7. The method as recited in claim 6, wherein the post-powder processing process is selected from the group consisting of thermal stress relieving, hot isostatic processing, solution heat treating, aging heat treating, grit blasting and combinations thereof. 